SARS-CoV-2-Specific Adaptive Immunity in COVID-19 Survivors With Asthma

Background Asthma patients potentially have impaired adaptive immunity to virus infection. The levels of SARS-CoV-2-specific adaptive immunity between COVID-19 survivors with and without asthma are presently unclear. Methods COVID-19 survivors (patients with asthma n=11, with allergies n=8, and COVID-19 only n=17) and non-COVID-19 individuals (asthmatic patients n=10 and healthy controls n=9) were included. The COVID-19 patients were followed up at about 8 months and 16 months after discharge. The clinical characteristics, lymphocyte subsets, memory T cells, and humoral immunity including SARS-CoV-2 specific antibodies, SARS-CoV-2 pseudotyped virus neutralization assay, and memory B cells were analyzed in these subjects. Results The strength of virus-specific T cell response in COVID-19 survivors was positively correlated with the percentage of blood eosinophils and Treg cells (r=0.4007, p=0.0188;and r=0.4435, p=0.0086 respectively) at 8-month follow-up. There were no statistical differences in the levels of SARS-CoV-2-specific T cell response between the COVID-19 survivors with, and without, asthma. Compared to those without asthma, the COVID-19 with asthma survivors had higher levels of SARS-CoV-2-specific neutralizing antibodies (NAbs) at the 8-month follow-up (p<0.05). Moreover, the level of NAbs in COVID-19 survivors was positively correlated with the percentage of Treg and cTfh2 cells (r=0.5037, p=0.002;and r=0.4846, p=0.0141), and negatively correlated with the percentage of Th1 and Th17 cells (r=-0.5701, p=0.0003;and r=-0.3656, p=0.0308), the ratio of Th1/Th2, Th17/Treg, and cTfh1/cTfh2 cell (r=-0.5356, r=-0.5947, r=-0.4485;all p<0.05). The decay rate of NAbs in the COVID-19 survivors with asthma was not significantly different from that of those without asthma at 16-month follow-up. Conclusion The level of SARS-CoV-2-specific NAbs in COVID-19 survivors with asthma was higher than that of those without asthma at 8-month follow-up. The SARS-CoV-2-specific T cell immunity was associated with blood eosinophils and Treg percentages. The SARS-CoV-2-specific humoral immunity was closely associated with cTfh2/cTfh1 imbalance and Treg/Th17 ratio. According to the findings, asthmatic patients in COVID-19 convalescent period may benefit from an enhanced specific humoral immunity, which associates with skewed Th2/Th1 and Treg/Th17 immune.

Application of a time-delay SIR model with vaccination in COVID-19 prediction and its optimal control strategy (preprint)

In the classical infectious disease compartment model, the parameters are fixed. In reality, the probability of virus transmission in the process of disease transmission depends on the concentration of virus in the environment, and the concentration depends on the proportion of patients in the environment. Therefore, the probability of virus transmission changes with time. Then how to fit the parameters and get the trend of the parameters changing with time is the key to predict the disease course with the model. In this paper, based on the US COVID-19 epidemic statistics during calibration period, the parameters such as incidence rate and recovery rate are fitted by using the linear regression algorithm of machine science, and the laws of these parameters changing with time are obtained. Then a SIR model with time delay and vaccination is proposed, and the optimal control strategy of epidemic situation is analyzed by using the optimal control theory and Pontryagin maximum principle, which proves  the effectiveness of the control strategy in restraining the spread of COVID-19. The numerical simulation results show that the time-varying law of the number of active cases obtained by our model basically conforms to the real changing law of the US COVID-19 epidemic statistics during calibration period. In addition, we have predicted the changes of the number of active cases in the COVID-19 epidemic in the United States over time in the future beyond the calibration cycle, and the predicted results are more in line with the actual epidemic data.

Can Thailand achieve COVID-19 herd immunity?

The COVID-19 outbreak has had a great impact on the social, economic, and health systems of Thailand. A variety of measures to curb the spread of the disease were implemented since the beginning of the pandemic, including a strict national lockdown protocol. The Thai government aimed to achieve herd immunity through an efficient vaccination programme. Initially, vaccine supply shortage and a lack of vaccine options plagued the health system, but this has since been improved. Continuous monitoring of the situation through research is being carried out to assess the level of immunity among the population whereby the current general recommendation is presently a fourth booster dose for adults. Hurdles towards achieving herd immunity remain. One such issue is the low level of vaccine literacy among those that are unvaccinated or inadequately vaccinated. Another obstacle is the sizeable rate of hesitancy towards getting booster doses. Achieving herd immunity in the Thai population would require multilateral cooperation, improved health promotion to target population groups, such as older adults, and a developed distribution system for those with limited access, such as those in the rural areas.

The Association between Trajectories of Loneliness and Physical Frailty in Chinese Older Adults: Does Age Matter?

Background: The present study aimed to examine age differences in the relationship between trajectories of loneliness and physical frailty among Chinese older adults. Methods: A total of 4618 participants aged ≥60 years old were taken from pooled data created from the 2011–2015 China Health and Retirement Longitudinal Study (CHARLS). Loneliness was assessed by a single question from the Centre for Epidemiological Studies scale, whereas physical frailty (PF) was examined by the physical frailty phenotype scale. We characterized trajectories of loneliness and PF using transition types and changes within the survey period. Results: Logistic regression models revealed that baseline loneliness was significantly related to remaining robust PF (OR = 0.55, 95% CI = 0.49–0.63, p < 0.001) and worsening in PF (OR = 1.17, 95% CI = 1.05–1.30, p < 0.01) at follow-up. Baseline PF status was also significantly related to the transitions in loneliness (worsen: OR = 1.41, 95% CI = 1.11–1.78, p < 0.01;improve: OR = 0.65, 95% CI = 0.47–0.91, p < 0.05). The cross-lagged panel model found that baseline PF or loneliness had a significant predictive effect on the changes in each other. The associations between trajectories of loneliness and PF were weakened with age and clustered in the under 75 age groups. Conclusions: Bidirectional associations may exist between trajectories of loneliness and PF among Chinese older adults. Interventions should mainly target the young-old to reduce the adverse reciprocal effects of loneliness and PF.

Practice and experience of regional medical center entrance linkage and closed-loop management under the wartime situation of the COVID-19 in China

On 28 July 2021, the first indigenous case of novel coronavirus pneumonia (COVID-19) emerged in Yangzhou, marking the beginning of a public health crisis caused by the new coronavirus pneumonia. It is a significant challenge for hospitals to carry out prevention and control measures to ensure the safety of medical professionals and patients when facing the changes in an epidemic situation. Subei People’s Hospital, as one of the first group of “Grade III-class A” hospitals in Jiangsu Province and the Yangzhou Regional Medical Centre, responded quickly and scientifically to prevent and control the disease. A closed-loop management system was implemented at the hospital entrance (consisting of the outpatient clinic, emergency clinic, fever clinic, and buffer ward) and an epidemic prevention and control group was established with the assistance of multiple departments. This group optimized the pre-screening and triage system, standardized the fever clinic consultation process, and improved the construction of an information-based prevention and control network so that patients were detected, diagnosed, isolated, and treated early. The emergency management capability was improved to achieve zero missed consultations of patients attending for COVID-19 and to effectively maintain medical order during this critical period. This current report systematically summarizes the operational practices and the effectiveness achieved by implementation of the entrance closed-loop management in the hospital and analyzed the key operational issues for future reference by medical institutions and management departments.

Assessment on Pedestrian-level Wind Around a Pocket Park with and Without Vegetation Inside Street Canyons

Creating a good local microclimate can alleviate urban heat islands and poor urban ventilation. During the COVID-19 epidemic, citizens' cross-city and cross-regional activities were restricted, and most activities were conducted in open/semi-open areas next to residential areas, and local pedestrians were also quantitatively explored. The new characteristics of the microclimate bring difficulties. The RNG k-ε model in the Reynolds time-average method is used to simulate and analyze the wind environment of a typical street valley with a pocket park in a hot summer and a cold winter, and explore whether there are plants in the pocket park. The results show that the results obtained by the used turbulence model, initial edge conditions and numerical method are in good agreement with the selected verification experimental results, which meet the needs of the wind environment simulation of the pocket park. Only under the action of the pocket park, the pedestrian area is dimensionless. The difference in wind speed can reach 0.5 compared to the time when there is no park. When the plants in the park are added, the average wind speed in the pedestrian area of ​​the surrounding street valley is less affected by the plants, and the dimensionless wind speed is only reduced by 0.1 in the core area of ​​the park. Pocket parks can significantly improve the low wind speed in pedestrian areas, and the research results can provide reference for the design of low-carbon livable blocks and microclimate simulation during the epidemic period.

[Variation Characteristics of Ambient Volatile Organic Compounds (VOCs) Volume Fraction During Hangzhou COVID-19 Period].

A continuous observation campaign was carried out with the Syntech Spectras GC955 volatile organics online monitoring system from December 1, 2019 to March 31, 2020 during the COVID-19 period in Hangzhou. Composition characteristics, diurnal variation, and atmospheric chemical reactivity of VOCs were analyzed. The results showed that φ(total VOCs) were the highest before the COVID-19 pandemic in different sites and the lowest during the first response period. The φ(total VOCs) at night was higher than that during the day. The daily variation in Wolongqiao φ(total VOCs) was less than that in Xiasha. The daily variation in φ(total VOCs) during the first level response period was less than that during the other three periods. The diurnal variation in the φ (total VOCs) in Xiasha showed a "V" shape, and that in Wolongqiao showed a typical bimodal structure. The OFP in Xiasha was higher than that in Wolongqiao. The OFP were the highest at the two sites before the COVID-19 pandemic. The OFP was the lowest during the first response period in Xiasha and the lowest during the second response period in Wolongqiao. The OFP of aromatics and olefins was higher, and the OFP of alkynes was the lowest in Xiasha. The OFP of olefin in Wolongqiao was much higher than that of the other three components, followed by alkane and alkyne.

The risk spillover effect of the COVID-19 pandemic on energy sector: Evidence from China

Detecting the adverse effects of major emergencies on financial markets and real economy is of great importance not only for short-term policy reactions but also for economic and financial stability. This is the lesson we learnt from the COVID-19 pandemic. This paper focuses on the risk spillover effect of the COVID-19 on Chinese energy industry using a high-dimensional and time-varying factor-augmented VAR model. The results show that the net volatility spillovers of the pandemic remain positive to all underlying energy sectors during January to June of 2020 and February to April of 2021. For the former sub-period, the volatility spillover of the COVID-19 is not only the highest, but also lasts longest for oil exploitation sector, followed by the power and gas sectors. While for the latter sub-period, the COVID-19 has relatively higher volatility spillovers to the power, coal mining and petrochemical sectors. These findings suggest that the COVID-19 has significant risk spillover effects on Chinese energy sectors, and the effects vary among different energy sub-sectors and across different periods of time.

Can Africa achieve herd immunity?

The World Health Organization described herd immunity, also known as population immunity, as the indirect fortification from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous exposure to infection. The emergence of COVID-19 vaccine is a step towards the achievement of herd immunity. Over one billion people across the globe have been vaccinated and Africa recorded only 2%. The objective of this article was to develop a forecast of the number of people to be vaccinated to achieve herd immunity in the 13 WHO-identified priority African countries for COVID-19. Herd immunity is achieved when one infected person in a population causes less than one secondary case on average, corresponding to the effective basic reproduction number (R0). Vaccine delivery and distribution infrastructure including the cold chain remains weak. Vaccine hesitancy is also one of the limiting factors that may hinder herd immunity in Africa. In order to achieve herd immunity globally, African countries should not be excluded in fair and equal distribution of vaccines. Relevant stakeholders should foster commitment as well as community sensitization on COVID-19 vaccines and integration of COVID-19 vaccines in existing healthcare services.

Influence of the First-wave COVID-19 Pandemic on Emergency Acute Coronary Syndrome: a Multicenter Retrospective Study From a Non-epicenter Region (preprint)

Background: The COVID-19 pandemic presented severe challenges to emergency practice of acute coronary syndrome (ACS). However, poor evidence was shown on ACS in a non-hot-spot region. We sought to clarify the influence of the first-wave COVID-19 pandemic on emergency ACS from a non-epicenter region. Methods: : This retrospective multicenter study was conducted in emergency ACS patients during the pandemic (from 2020-01-23 to 2020-03-29) and the ones during the same period in 2019. Clinical characteristics, timeline parameters and treatment strategies were compared between different groups. Association of the pandemic with non-invasive therapy was further assessed. Results: : Compared with 2019, ACS had a drop in admission (267 cases vs. 475 cases) and invasive therapy (140 cases vs. 318 cases). Also, process delays were detected including the period from symptom onset to first medical contact (S-to-FMC, 5h vs. 2.5h), the period from FMC to electrocardiogram (ECG) completed (8min vs. 4min) and the period from FMC to dual antiplatelet therapy (FMC-to-DAPT, 25min vs. 19min). Primary percutaneous coronary intervention (PPCI) decreased by 54.9% in STEMI and early invasive therapy decreased by 59.2% in NSTE-ACS. The proportion of invasive therapy in NSTE-ACS decreased more than in STEMI (16.9% vs. 10.1%) with longer process delay. The pandemic was associated with increased non-PPCI in STEMI (OR=1.707, 95%CI 1.082-2.692, P=0.021) and elevated medication in NSTE-ACS (OR=2.029, 95%CI 1.268-3.247, P=0.003), respectively. Conclusion: Even in a non-epicenter region, the first-wave COVID-19 pandemic caused a significant reduction of invasive therapy and evident process delays in emergency ACS.

Improving sentiment analysis accuracy with emoji embedding

Due to the diversity and variability of Chinese syntax and semantics, accurately identifying and distinguishing individual emotions from online texts is challenging. To overcome this limitation, we incorporate a new source of individual sentiment, emojis, which contain thousands of graphic symbols and are increasingly being used for expressing emotion in online conversations. We examined popular sentiment analysis algorithms, including rule-based and classification algorithms, to evaluate the impact of supplementing emojis as additional features to improve the algorithm performance. Emojis were also translated into corresponding sentiment words when constructing features for comparison with those directly generated from emoji label words. In addition, considering different functions of emojis in texts, we classified all posts in the dataset by their emoji usage and examined the changes in algorithm performance. We found that emojis are effective as expanding features for improving the accuracy of sentiment analysis algorithms, and the algorithm performance can be further increased by taking different emoji usages into consideration. In this study, we developed an improved emoji-embedding model based on Bi-LSTM (namely, CEmo-LSTM), which achieves the highest accuracy (around 0.95) when analyzing online Chinese texts. We applied the CEmo-LSTM algorithm to a large dataset collected from Weibo from December 1, 2019 to March 20, 2020 to understand the sentiment evolution of online users during the COVID-19 pandemic. We found that the pandemic remarkably impacted individual sentiments and caused more passive emotions (e.g., horror and sadness). Our novel emoji-embedding algorithm creatively combined emojis as well as emoji usage with the sentiment analysis model and can handle emotion mining tasks more effectively and efficiently.

Genomic evidence for divergent co-infections of SARS-CoV-2 lineages (preprint)

Recently, patients co-infected by two SARS-CoV-2 lineages have been sporadically reported. Concerns are raised because previous studies have demonstrated co-infection may contribute to the recombination of RNA viruses and cause severe clinic symptoms. In this study, we have estimated the compositional lineage(s), tendentiousness, and frequency of co-infection events in population from a large-scale genomic analysis for SARS-CoV-2 patients. SARS-CoV-2 lineage(s) infected in each sample have been recognized from the assignment of within-host site variations into lineage-defined feature variations by introducing a hypergeometric distribution method. Of all the 29,993 samples, 53 (~0.18%) co-infection events have been identified. Apart from 52 co-infections with two SARS-CoV-2 lineages, one sample with co-infections of three SARS-CoV-2 lineages was firstly identified. As expected, the co-infection events mainly happened in the regions where have co-existed more than two dominant SARS-CoV-2 lineages. However, co-infection of two sub-lineages in Delta lineage were detected as well. Our results provide a useful reference framework for the high throughput detecting of SARS-CoV-2 co-infection events in the Next Generation Sequencing (NGS) data. Although low in average rate, the co-infection events showed an increasing tendency with the increased diversity of SARS-CoV-2. And considering the large base of SARS-CoV-2 infections globally, co-infected patients would be a nonnegligible population. Thus, more clinical research is urgently needed on these patients.

Acceptability of COVID-19 Vaccination in Herat, Afghanistan (preprint)

Background: COVID-19 vaccine hesitancy is one of the major concerns in the roll out of vaccines in many countries. The aim of the study was to assess the level of COVID-19 vaccine acceptability among the population in Herat, Afghanistan, the third largest city in the country. Methods: : This cross-sectional study was conducted between 15 April 2021 and 20 April 2021 among the general population of Herat City to examine the acceptability rate of COVID-19 vaccine. Sample size was calculated at 555. Different variables were collected using a questionnaire developed. Data were evaluated in IBM SPSS program. Results: : Only 10.63% of the participants were willing to receive COVID-19 vaccine without having any concern and reservation. 45% were willing to receive the COVID-19 vaccine. 66.5% were concerned about the vaccine and its side effects and 29% were afraid of being infected by transmission of COVID-19 through the administration of vaccine on them. Conclusion: This research demonstrates that, concerns about the vaccine, myths and misinformation are widespread which will undermine the vaccination process. This study recommends the initiation of more health-related campaigns and awareness programs by the government for general population to enhance and expedite the roll out of COVID-19 vaccine.

Practice of New Normal Lifestyles, Economic and Social Disruption, and Level of Happiness Among General Public in China in the Post-COVID-19 Era.

PURPOSE: This study aimed to investigate the impact of the COVID-19 pandemic on the practice of 'new normal' lifestyles, economic and social distribution, and individuals' well-being of people in China after the country ease the lockdown restriction. METHODS: A cross-sectional, self-administered online survey was carried out between 3 September and 15 October 2020. RESULTS: A total of 8393 complete responses were received from a nationwide sample. Poor sustainability in the practice of "new norm" was reported. Noteworthy disparities were observed in willingness to carry out "new normal" practices by gender, urban-rural locality, non-Han and Han Chinese and educational attainment. There was evidence of economic and social disruption associated with COVID-19 or "new normal" practices. The current mean (±standard deviation [SD]) happiness score (110.45 ± 17.55) was slightly lower than the mean happiness score before (111.12 ± 17.83) the COVID-19 pandemic (t= -9.01, p<0.001). Lower socioeconomic status and greater economic and social disruptions were associated with lower current happiness scores. Moreover, greater willingness to adapt to "new normal" practices was associated with higher levels of happiness. CONCLUSION: There is a need to encourage sustainable practice of new norm post-pandemic. Segments of the public continue to experience significant economic and social effects and the post-pandemic 'new norms' remain at risk of leading to psychological consequences.